1. Field of the invention.
The invention is in the field of polarizing retroreflecting prisms convenient for use in lasers and optical scanning or similar systems.
2. Description of prior art.
There are many type prisms used in the various state-of-the-art optical systems. A particular prism may be constructed to deviate, displace, and reflect light in various ways and to reflect or refract an image in combinations of normal, erect, inverted, and reverted images. Prisms may be used in laser systems or optical scanning systems to provide polarization of the laser light, Q-switching of the laser, sweep of an image, offset of a light beam, or the like. The use of the present polarizing retroreflecting prism, say as the so called 100% reflecting end mirror of a laser cavity or for image sweeping in an optical scanning system, solves many inherent problems. Not only must the laser reflecting end mirrors have extremely high reflectivity for laser propagation but also must be aligned with expensive micrometer adjusted laser mirror mounts and should have a long life free of chemical degradation of exposed optical coatings. Further, a polarized beam is essential to many laser applications and a separate Brewsters window is used along with the reflecting end mirror. All of the above problems can be solved with the present polarizing retroreflecting prism, and when compared to mirrors currently used in lasers has major advantages in simplicity, effectiveness, and low cost.